Promise.all returning undefined in Node JS - node.js

Question

I have a code to fetch directory names from first API. For every directory, need to get the file name from a second API. I am using something like this in my Node JS code -
async function main_function(req, res) {
const response = await fetch(...)
.then((response) => {
if (response.ok) {
return response.text();
} else {
return "";
}
})
.then((data) => {
dirs = ...some logic to extract number of directories...
const tempPromises = [];
for (i = 0; i < dirs.length; i++) {
tempPromises.push(getFilename(i));
}
console.log(tempPromises); // Prints [ Promise { <pending> } ]
Promise.all(tempPromises).then((result_new) => {
console.log(result_new); // This prints "undefined"
res.send({ status: "ok" });
});
});
}
async function getFilename(inp_a) {
const response = await fetch(...)
.then((response) => {
if (response.ok) {
return response.text();
} else {
return "";
}
})
.then((data) => {
return new Promise((resolve) => {
resolve("Temp Name");
});
});
}
What am I missing here?

Answer 1

Your getFilename() doesn't seem to be returning anything i.e it's returning undefined. Try returning response at the end of the function,
async function getFilename(inp_a) {
const response = ...
return response;
}

Answer 2

Thanks to Mat J for the comment. I was able to simplify my code and also learn when no to use chaining.
Also thanks to Shadab's answer which helped me know that async function always returns a promise and it was that default promise being returned and not the actual string. Wasn't aware of that. (I am pretty new to JS)
Here's my final code/logic which works -
async function main_function(req,res){
try{
const response = await fetch(...)
const resp = await response.text();
dirs = ...some logic to extract number of directories...
const tempPromises = [];
for (i = 0; i < dirs.length; i++) {
tempPromises.push(getFilename(i));
}
Promise.all(tempPromises).then((result_new) => {
console.log(result_new);
res.send({ status: "ok" });
});
}
catch(err){
console.log(err)
res.send({"status" : "error"})
}
}
async function getFilename(inp_a) {
const response = await fetch(...)
respText = await response.text();
return("Temp Name"); //
}